Method of treating matte.



UNITED STATES PATENT OFFICE.

WUOLSEY McA. JOHNSON, OF HARTFORD, CONNECTICUT.

METHOD OF TREATlNG MATTE.

Specification of Letters Patent.

Patented March 6, 1906.

Application filed May 27, 1903. Serial No. 168.936.

To ctZZ whom it may concern:

Be it known that I, WOOLSEY MoA. JOHN- son, a citizen of the United States, residin at Hartford, in the county of Hartford an State of Connecticut, have invented certain new and useful Im rovements in Methods of Treating Matte, 0 which the following is a specification.

This invention is a method of treating cepper nickel matte and separating therefrom some or all of the contained metals either in gluline form or as oxids.

he method will be described by reference to one specific exam le thereof.

The cop er-nicke matte in the specific instance to e described may contain thirtynine per cent. of nickel, thirty-nine per cent. of copper, substantially one per cent. each of iron and cobalt, and twenty per cent. of sulfur, together with small roportions of plati num and palladium. '1 us matte is crushed, passed through sixty or eighty mesh screens, placed in dissolving or leaching vats of any suitable construction provided with agitators and subjected therein to the action of a hot. solution of sulfuric acid preferably of about five per cent. concentration and at a temperature of 80 to 100 centigrade. The leachlug-vats may be provided with any suitable means for heating the acid solution, as is well understood in the art. Said vats should be covered and provided with means for conducting away the h drogen sulfid formed by reaction of the aci upon the sulfids of the matte. This hydro en sulfid is conducted to a suitable fine and there burned with admixture of air to form sulfur dioxid, according to the reaction,

The sulfur dioxid so produced may be converted into sulfuric acid according to known methods, such acid bein sold as a by-prod' not or being employed, if desired, for leaching the matte or or treatin the residue there of, as hereinafter described I The solution obtained contains "nickel, cobait, and iron as sulfates. Said solution is freed from cobalt and iron preferablv by treatment with chlorin and caustic soda or sodium carbonate, or bv the action of hypochlorites, according to own methods, said chlorin and caustic soda or hypochlorites being preferably prepared by the electrolytic ,decom osition of sodium-chlorid solutions.

The co alt is recovered from the precipitate asoXid,(Co O,,)and may besold assuch. The resultant nickel-sulfate solution is than treated with caustic soda, whereby the nickel is separated as hydrate, said hydrate being, if desired, dried, calcined, and reduced to metal or the nickel-sulfate solution may be electrolyzed with insoluble anedesto obtain the metal, nickel hydroxid being added to the electrolyte and dissolved by the acid liberated, whereby the substantial neutrality of the solution is maintained at all times; or I may proceed as follows: Nickel h droxid precipitated as above stated is disso ved to neutralization by sulfuric acid, and the nickel sulfate solution resulti is electrolyzed, nickel being separated an nickel hydrate being added to or being present in the bath and passing into solution as fast as the nickel is precipitated, thereby keeping the solution neutral; or, if desired, the nickel bydroxid may be dissolved in hydrochloric acid and the resulting nickel-chlorid solution electrolyzed with anodes of aphite in acell provided with a diaphra m, t d nickel bein separated as metal and t e chlorin utilized lor the production of liquid chlorin or bleaching-powder.. The residue from the acid treatment of the matte consists chiefly of copper sulfid, togather with such quantities of platinum and palladium as may have been present in the original matte, and a roportion of undissolved nickel sulfid. This residue is roasted to oxid, the gases evolved being )referably assed through the copper electrolyte, hereinafter described. The roasted residue is treated with sulfuric acid, whereby a solution is obtained which may contain, in the specific example given, substantial? nine or cent. of copper and one per cent. 0 nickel in the form of sulfates. Said solution is electrolyzed with anodes of lead, the gases from the roasting operation being passed through the bath, said gases serving the double purpose of reducing the electromotive force necessary for the electrolysis and yielding sulfuric acid in such quantity that the acid formed during the precipitation of a given quantity of copper upon the cathode is sulficient to subsequently dissolve both the nickel and copper of the residue. This electrplysis is continued until the copper content of the electrolyte is reduced to about 0.8 per cent. or tosueh other proportion as maybe desired, and the spent arid electrolyte containing also the arid derived from the roastin gases is thereupon returned to the liquid in t e vats for the leaching of roasted residue. The solution formed is again elcctrolyzed, as above described.

When the proportion of nickel in this copper electrolyte has risen to such an extent as to interfere with the deposition of copper, (say eight per cent. nickel as a limit,) the electrolyte 1s pumped to a second series of electrolytic vats provided with rotar Y cathodes and electrolyzed therein until t 18-001)- pcr is reduced to about 0.4 per cent. This electrolyte is then returned to the vats for leachin the original matte. In such vats the sul uric acid in the spent copper electrolyte is available for the solution of further amounts of iron, cobalt, and nickel, while the remaining copper is precipitated by the hydrogen sulfid evolved by the treatment, the small quantities of cupric sulfid thereby formed remaining with the residue in these vats and being again roasted and dissolved therewith in the continuation of the treatment, as above described.

The undissolved residue from the treatment of the roasted residue from the vats is worked according to known chemical methods for the separation of platinum and palladium.

1. The herein-described method which conslsts in subjecting copper-nickel matte to the action of sulfuric acid, thereby dissolving nickel and liberating hydrogen sulfid, and leaving a residue consisting in part of copper sulfid; roasting said residue to oxid and leachlng same with sulfuric acid, thereby forming a solution containing copper sulfate; electrolyzing said solution to separate a portion of the copper; and returning the s ent electrolyte to the leachingvats, as set orth.

2. The herein-described nicthod which consists in subjecting copper-nickel matte to the action of hot dilutc sulfuric acid, thereby dissolving nickel and liberating hydrogen sulfid, and leaving a residue consisting in part of copper sulfid; roasting said residue to oxid and leaching same with sulfuric acid, thereby forming a solution containing copper sulfate; clectrolyzing said solution to separate a portion of the cop er; and returning the spent electrolyte to the leaching-vats, as set forth.

3. The herein-described method which consists in subjecting copper-nickel matte to the action of sulfuric acid, thereby dissolving nickel and liberating hydrogen sulfid, and leaving a residue consisting in part of cop er sulfid; recovering the nickel from the so ution roasting said residue to oxid and leaching same with sulfuric acid, thereby forming a solution containing copper sulfate; electrolyzing said solution to separate a portion of the copper; and returning the spent eleetrolyte to the leaching-vats, as set forth.

4. The herein-described method which consists in subjecting cop er-nickel matte to the action of hot dilute su furie acid, thereby dissolving nickel and liberating hydrogen sulfid, and leaving a residue consisting in part of co per sulfid; recovering the nickel from the so ution; converting. said hydrogen sullid to sulfuric acid; roastin said residue to oxid and leaching same witTi sulfuric acid, thereby formin a solution containing copper sulfate; electro yzing said solution to separate-a portion of the copper, and returning the remaining solution to the leaching-vats, as set forth.

5. The herein-described method which consists in subjecting copper-nickel matte to the action of sulfuric acid, thereby dissolvin r nickel and liberating hydrogen sullid, an leaving a residue consisting in part of copper sulfid, roasting sa d residue to oxid and leaching same with sulfuric acid, thereby forming a solution containing copper sulfate; electrolyzing said solution to separate a portion of the copper; returning the solution to the roasted residue and repeating theelcetrolysis, and finally returning the spent electrolyte to theleacbing-vats for the matte, as set forth.

6. The herein-described method which eonsists in subjecting copper-nickel matte to the action of sulfuric acid, thereby dissolvin r nickel and liberating hydrogen sulfid, an leaving a residue consisting in part of copper sulfid roasting said residue to oxid and leaching same with sulfuric acid, thereby forming a solution containing copper sulfate; electrolyzing said solutionto separate a portion of the co per; returning the solution to the roaste residue and repeating the electrolysis until the presence of nickel interferes with the deposition of the copper; depositing further quantities of copper upon rotary cathodes, and finally returning the spent electrolyte to the leaching-vats for the matte, as set forth.

7. The hereindescribed method of electrolyzing nickel solutions, which consists in maintainin the bath in a state of substantial neutrality by the solution therein of nickel hydroxid, as set forth.

3. The herein-described method of electrolyzing nickel solutions which consists in adding to the bath nickel hydroxid in quantity proportionate to the metal separated at the cathode, whereby the substantial neutrality of the bath is maintained, as set forth.

9. The herein-described method of treatin material containing nickel and copper as so lids, which consists in roasting the same, dissolving the roasted residue in sulfuric acid, electrolyzing the solution with insoluble anodes while passing into the electrolyte the gases derived from the roastin operation, and returnin the acid electro yte to the roasted material, as set forth.

10. The herein-described method of treatin material containing nickel and copper es ds, which consists in roasting the same, dissolving the roasted residue in sulfuric acid, eleotrolyzing the solution with anodes of lead while passing into the electrolyte the gases derived from the roastin operation, :0 and returning the acid eleetro yte to the roasted material, as set forth. I In testimony whereof I afiix my signature in presence of two witnesses.

WOOLSEY MoA. JOHNSON. Witnesses:

CHARLES M. STARKWEATHER, O. V. MARSH. 

